select a range of elements from a nested list

*To*: mathgroup at smc.vnet.net*Subject*: [mg5387] select a range of elements from a nested list*From*: Oliver Schurr <schurro at gusun.acc.georgetown.edu>*Date*: Thu, 5 Dec 1996 14:50:24 -0500*Sender*: owner-wri-mathgroup at wolfram.com

Hi MathGroup Say you have a nested list like that {{x1,y1},{x2,y2},{x3,y3},...{xn,yn}} basically containing X and Y values for a XY plot in each element. The X values span a range from say 0 to 0.4 and you ONLY want to select the elements (x,y values) from the list for which the x value spans say 0 to 0.3. BUT you don't want to COUNT the elements (visually on the screen) and figure out the position at which the x value is just greater than 0.3 and then subtract 1 from this position. I still want do define the list by using Table[list[[x,1]],list[[x,2]],{x, 1, ZZZ}] here ZZZ means the number for which the x value <= 0.3, this number needs to be found by MATHEMATICA! I like to know if there is a general procedure to select elements from a nested list based on the values of one member of the elements of that nested list. I hope I made myself clear enough to you all. Thanks a lot. Oliver Schurr Department of Chemistry Georgetown University Washington, DC 20057